The coil sprung rear fitted to ARP4, ARV6 and later 3.7 Roadsters forced MMC into providing positive axle location with upper and lower trailing arms and panhard rod. It's left to individuals to add axle location devices via specialist springs, anti-tramp bars and panhard rods on leaf sprung models though, should they feel the need.
The exception was the leaf sprung Roadsters but was surprised to find only one anti-tramp bar was factory fitted even to the 3.7 version. Clearly the tractive axle wind up marginally benefits fitting one side rather than the other but it's pure penny pinching not to have both. Below is video of the latter ex factory. The camera location showing the nose of diff and axle twist is most alarming.
https://www.youtube.com/watch?v=otP5xU8qvYYFollowing fitting of second anti-tramp bar and panhard rod, a second video by same owner.
https://www.youtube.com/watch?v=yaVDqJEEKR8
